High level of stress, cholesterol, hormonal imbalance, chain smoking, dramatic changes in
your life style may be some of the common causes of you irregular periods
Menarche and menopause are also important causes of irregular periods. Some time is taken for the body to get used to the hormonal imbalance during menarche and menopause. So the irregularity.
Are you having heavy bleeding or pain during menstruation along with the irregularity?